Sensor assembly and motor including the same

Abstract

Disclosed herein are a sensor assembly including a holder that includes a first insertion groove formed at one side and a second insertion groove formed at the other side, a sensing magnet disposed at the first insertion groove, and a sensor cap that covers the sensing magnet, and a motor including the same.

What is claimed is: 
     
       1. A sensor assembly comprising:
 a holder including a side surface and a bottom surface; 
 a first insertion groove formed in the bottom surface of the holder; 
 a sensing magnet disposed in the first insertion groove, a bottom surface of the sensing magnet extending below the bottom surface of the holder; and 
 a sensor cap configured to cover the sensing magnet, the sensor cap having a bottom portion contacting the bottom surface of the sensing magnet, and a side portion extending over and fixed to the side surface of the holder. 
 
     
     
       2. The sensor assembly of  claim 1 , wherein the holder includes a second insertion groove formed at a top surface of the holder, and
 wherein the second insertion groove serves to be coupled to a rotation shaft of a motor. 
 
     
     
       3. The sensor assembly of  claim 1 , wherein a depth of the first insertion groove is smaller than a thickness of the sensing magnet. 
     
     
       4. The sensor assembly of  claim 1 , wherein the holder includes a recessed groove formed in a circumferential direction, and
 wherein a fastening portion of the side portion of the sensor cap engages the recessed groove to fix the sensor cap to the holder. 
 
     
     
       5. The sensor assembly of  claim 1 , wherein the holder includes a ring-shaped wing portion configured to protrude in a radial direction from the side surface of the holder, and
 wherein a diameter of the wing portion is 1.2 to 2.0 times a diameter of the holder. 
 
     
     
       6. The sensor assembly of  claim 1 , wherein the holder and the sensor cap include a nonmagnetic material. 
     
     
       7. The sensor assembly of  claim 1 , wherein the bottom portion of the sensor cap directly contacts the bottom surface of the sensing magnet. 
     
     
       8. The sensor assembly of  claim 1 , wherein a thickness of the sensor cap is 0.05 mm to 0.3 mm. 
     
     
       9. The sensor assembly of  claim 1 , wherein the sensor cap includes a connection portion configured to connect the bottom portion and the side portion to each other, and the connection portion has a curvature. 
     
     
       10. The sensor assembly of  claim 1 , wherein the sensor cap includes a plurality of protrusions formed at the bottom portion. 
     
     
       11. The sensor assembly of  claim 1 , wherein the sensor cap includes a central hole formed at a center of the bottom portion and a plurality of sub-holes formed at an outside of the bottom portion. 
     
     
       12. The sensor assembly of  claim 1 , further comprising:
 grooves formed in a bottom surface of the first insertion groove; and 
 adhesive on the bottom surface of the first insertion groove, 
 wherein a top surface of the sensing magnet contacts the adhesive to retain the sensing magnet in the first insertion groove. 
 
     
     
       13. A motor comprising:
 a rotation shaft; 
 a rotor including a hole into which the rotation shaft is inserted; 
 a stator disposed along an outer perimeter of the rotor; 
 a housing configured to accommodate the rotor and the stator; and 
 a sensor assembly configured to detect a rotation of the rotor, wherein the sensor assembly includes: 
 a holder including a side surface and a bottom surface; 
 a first insertion groove formed in the bottom surface of the holder; 
 a sensing magnet disposed at the first insertion groove, a bottom surface of the sensing magnet extending below the bottom surface of the holder; and 
 a sensor cap configured to cover the sensing magnet, the sensor cap having a bottom portion contacting the bottom surface of the sensing magnet, and a side portion extending over and fixed to the side surface of the holder. 
 
     
     
       14. The motor of  claim 13 , further comprising a detection unit configured to sense a rotation of the sensing magnet. 
     
     
       15. The motor of  claim 14 , wherein the detection unit includes a magnetic element configured to face the bottom portion of the sensor cap, and a printed circuit board on which the magnetic element is disposed. 
     
     
       16. The motor of  claim 13 , wherein the holder includes a second insertion groove formed at a top surface of the holder, and the second insertion groove is coupled to the rotation shaft of the motor. 
     
     
       17. The motor of  claim 13 , wherein a depth of the first insertion groove is smaller than a thickness of the sensing magnet. 
     
     
       18. The motor of  claim 13 , wherein the holder includes a recessed groove formed in a circumferential direction, and
 wherein a fastening portion of the side portion of the sensor cap engages the recessed groove to fix the sensor cap to the holder. 
 
     
     
       19. The motor of  claim 13 , wherein the holder includes a ring-shaped wing portion configured to protrude in a radial direction from the side surface of the holder, and
 wherein a diameter of the wing portion is 1.2 to 2.0 times a diameter of the holder. 
 
     
     
       20. The motor of  claim 13 , wherein the holder and the sensor cap include a nonmagnetic material.